Project description:H3K27 di-methylation and H3K27 trimethylation are marks of facultative heterochromatin which maintains transcriptional repression established during early development in many eukaryotes. However, the mechanism underlying establishment and regulation of epigenetic asymmetry in the zygote remains obscure. Here we report the distribution pattern of H3K27me2 in Ezh2m+/p+ and Ezh2m-/p+ mice zygotes using the approach of ULI-NChIP.
Project description:PABPN1L participates in the process of post-transcriptional regulation and degradation of maternal mRNA.We collect samples of each period from pabpn1l ko and wt female mice during different stages. Each group contained a total of 30 oocytes or zygotes. In the initial step, we spiked 2 × 106 mRNA-EGFP, transcribed in vitro, into each group.Then, RNA was extracted and detected.Reverse transcription was performed on the samples that met the effective concentration.After quality inspection, build the library.GV oocytes, MII oocytes and zygotes were collected from three different PABPN1L KO or WT mice seperately.
Project description:PABPN1L participates in the process of post-transcriptional regulation and degradation of maternal mRNA.So,we collect samples of each period from pabpn1l ko and wt female mice during different stages.Then, RNA was extracted and detected.Reverse transcription was performed on the samples that met the effective concentration.After quality inspection, build the library.GV oocytes, MII oocytes and zygotes were collected from three different PABPN1L KO or WT mice separately.
Project description:After the library was qualified, the library was pooled according to the effective concentration and the demand of target offline data, and was sequenced by Illumina platform. Since PABPN1L can bind the poly(A) tail, we propose that it participates in the process of post-transcriptional regulation and degradation of maternal mRNA. We investigated the mRNA changes in GV oocytes, MII oocytes, and fertilized eggs using RNA-seq. GV oocytes, MII oocytes and zygotes were collected and mixed from three mice of each genotypes separately.
Project description:Our data provided a genome-wide DNA methylation landscape of human early development embryos, including human MII oocytes, sperm, zygotes, 2-cell to 8-cell embryos, morula, blastocyst and postimplantation embryos at single base resolution. In total, 44 samples including biological and technical replicates, from 12 different human embryo development stages were analyzed, including two metaphase II oocytes, two zygotes, three first polar bodies, two second polar bodies, four sperm samples, two 2-cell-stage embryos, two 4-cell-stage embryos, three 8-cell-stage embryos, three morulae, three inner cell masses (ICMs) and three trophectoderms (TEs) seperated from late blastocysts, and three post-implantation embryos. In addition, 12 different human embryo development stages were analyzed, including metaphase II oocytes, zygotes, first polar bodies, second polar bodies, sperm samples, 2-cell-stage embryos, 4-cell-stage embryos, 8-cell-stage embryos, morulae, inner cell masses (ICMs) and trophectoderms (TEs) seperated from late blastocysts, and post-implantation embryos.
Project description:Fertilization triggers a global erasure of 5-methylcytosine from paternal DNA as part of extensive epigenetic reprogramming during the transition from gametic specialization to totipotency. This active removal has been shown to involve oxidation by TET3, but the targeting of this pathway and the wider context of demethylation remain poorly understood. We optimized a novel technique for whole-genome bisulfite sequencing and applied it to wild-type and TET3-deficient zygotes, using SNPs to access paternal alleles. As the great majority of sperm-contributed methylation lies outside the CpG islands (CGIs) and promoters analysed to date, these genome-wide methylation profiles allow paternal methylation trajectories in the zygote to be comprehensively examined for the first time. This global view revealed that in addition to pervasive loss of methylation from intergenic sequences and most repetitive elements, gene bodies constitute a major target of zygotic demethylation. Methylation loss is associated with zygotic genome activation, and at gene bodies is also linked to increased transcriptional noise in the early embryo. Our data maps the primary contribution of oxidative demethylation to a subset of gene bodies and single-copy intergenic sequences, and implicates the action of redundant pathways at many loci. We further uncover a novel function for TET3 in protection from de novo methylation at CGIs and promoters. This work adds new breadth to our understanding of the molecular events involved in reprogramming gametic identity following fertilization. Three independent collections of zygotes were performed for each genotype (control and TET3 deletion), giving a total of 225 control and 237 TET3 deletion zygotes, of which 120 and 129 were derived from 129S2/SvHsd studs for control and TET3 samples, respectively. Zygotes were pooled and whole-genome bisulfite libraries were prepared using a post-bisulfite adaptor tagging strategy optimized from (Miura et al. Nucleic Acids Research 2012, 40:e136)
Project description:Transposable elements (TEs) are widely represented in eukaryotic genomes. Recently, a set of small RNAs known as rasRNAs (repeat-associated small RNAs) have been related to the down-regulation of TEs conferring a means to safeguard genome integrity. Two key members of the rasRNAs group are piRNAs and endo-siRNAs. In this study, we have performed a comparative analysis of piRNAs and endo-siRNAs present in mouse oocytes, spermatozoa and zygotes, identified by deep sequencing and bioinformatic analysis. Both piRNAs and endo-siRNAs regulate TEs in addition to other repetitive elements such as tRNAs and rRNAs, suggesting an alternative role of rasRNAs with regard to translation regulation. The detection of piRNAs and endo-siRNAs in sperm cells and revealed also in zygotes, hints to their potential delivery to oocytes during fertilization. However, a comparative assessment of the three cell types indicates that both piRNAs and endo-siRNAs are mainly maternally inherited. Finally, we have assessed the role of the different rasRNA molecules in connection with amplification processes by way of the “ping-pong cycle”. Our results suggest that the ping-pong cycle can act on other rasRNAs, such as tRNA- and rRNA-derived fragments, thus not only being restricted to TEs during gametogenesis, as was evidenced in spermatozoa, oocytes and zygotes.
Project description:Our data provided a genome-wide DNA methylation landscape of human early development embryos, including human MII oocytes, sperm, zygotes, 2-cell to 8-cell embryos, morula, blastocyst and postimplantation embryos at single base resolution.